When mvn install fails cryptically -

Question

I have a maven project with unit tests, and I get a large exception trace when running "mvn install". Surprisingly -- this stacktrace actually doesn't result in failure of the task ! It appears that it is related to the availability of Junit libraries...

1) Id like to know how to fix this (obviously) for this project so that the libraries are available and the tests run (yes, Junit4 is in the pom.xml dependencies).

2) What the best way to definitively debug this and find the root cause is ?

3) Why does Maven say "build success" when clearly the surefire utility threw a nasty exception ?

org.apache.maven.surefire.util.SurefireReflectionException: java.lang.reflect.InvocationTargetException; nested exception is java.lang.reflect.InvocationTargetException: null java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:164) at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:110) at org.apache.maven.surefire.booter.SurefireStarter.invokeProvider(SurefireStarter.java:172) at org.apache.maven.surefire.booter.SurefireStarter.runSuitesInProcessWhenForked(SurefireStarter.java:104) at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:70) Caused by: java.lang.NoClassDefFoundError: Test at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2427) at java.lang.Class.getMethod0(Class.java:2670) at java.lang.Class.getMethod(Class.java:1603) at org.apache.maven.surefire.util.ReflectionUtils.tryGetMethod(ReflectionUtils.java:57) at org.apache.maven.surefire.common.junit3.JUnit3TestChecker.isSuiteOnly(JUnit3TestChecker.java:65) at org.apache.maven.surefire.common.junit3.JUnit3TestChecker.isValidJUnit3Test(JUnit3TestChecker.java:60) at org.apache.maven.surefire.common.junit3.JUnit3TestChecker.accept(JUnit3TestChecker.java:55) at org.apache.maven.surefire.common.junit4.JUnit4TestChecker.accept(JUnit4TestChecker.java:52) at org.apache.maven.surefire.util.DefaultDirectoryScanner.locateTestClasses(DefaultDirectoryScanner.java:80) at org.apache.maven.surefire.junit4.JUnit4Provider.scanClassPath(JUnit4Provider.java:174) at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:83) ... 9 more Caused by: java.lang.ClassNotFoundException: Test at java.net.URLClassLoader$1.run(URLClassLoader.java:202) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) at java.lang.ClassLoader.loadClass(ClassLoader.java:247) ... 21 more

POM is below

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>rudolf</groupId>
    <artifactId>r1</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>r1</name>
    <url>http://maven.apache.org</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-io</artifactId>
            <version>1.3.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.derby</groupId>
            <artifactId>derby</artifactId>
            <version>10.9.1.0</version>
        </dependency>
        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java</artifactId>
            <version>2.4.0a</version>
        </dependency>
    </dependencies>


    <build>
        <plugins>
          <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.9</version>
            <executions>
                <execution>
                    <phase>test</phase>
                    <goals>
                        <goal>test</goal>
                    </goals>
                </execution>
            </executions>
          </plugin>          
          <plugin>
             <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-compiler-plugin</artifactId>
             <version>2.3.2</version>
             <configuration>
               <source>1.6</source>
               <target>1.6</target>
             </configuration>
           </plugin>
        </plugins>
    </build>



    <pluginRepositories>
        <pluginRepository>
            <id>onejar-maven-plugin.googlecode.com</id>
            <url>http://onejar-maven-plugin.googlecode.com/svn/mavenrepo</url>
        </pluginRepository>
    </pluginRepositories>
</project>

Are you running from the command line? The subject says Eclipse. — Dave Newton, Nov 07 '12 at 17:32
Do all your test classes contains at least one method annotated with `@Test`. I think I may have seen this problem before when I had an empty test class. — Jesse Webb, Nov 07 '12 at 18:04
Do you have a mixture of junit3 and junit4 tests? (And do you have junit3 suites)? And can you try with a later version of JUnit? You're using 4.1. Can you try with 4.10? — Matthew Farwell, Nov 07 '12 at 18:28
@matthewFarwell this was part of the solution - if you formalize it as an answer then i owe u credit — jayunit100, Nov 07 '12 at 22:27

score 3 · Accepted Answer · edited May 23 '17 at 12:22

This is definetly a perfect storm of silliness:

1) My Test Classes is not named according to the default surefire regular expressions See related Maven does not find JUnit tests to run. So the tests weren't really running.

2) The Test that DID run was actually doing some JVM hacking, using classes like "Unsafe" - causing a segmentation fault. This segmentation fault mucks with the overall Maven build, corrupting the result of the maven output.

The take home lessons are:

1) (not 100% sure, but it appears ) -- If some odd low level failure occurs in the JVM during a mvn build, one might expect strange results at the end which dont simply indicate errors/failures in the proper manner

2) Default Junit test case for surefire behaviour doesnt just run all @Test methods in a package automatically - classes have to be named appropriately or you have to manually edit the surefire pattern filters.

Hi @jayunit100 : could you please let me kno what changes to did to remove this error. As i am too getting the same error with "Build Success". Could you please help me. — techGaurdian, Sep 07 '15 at 12:47
Avoid mixing junit test versions 3/4, avoid doing jvm hacks in unit tests if you can, otherwise, I can't recall — jayunit100, Sep 07 '15 at 19:04

Ted_Zactly · Answer 2 · 2015-04-15T21:40:13.647

0

I've run into a problem like this with TestNG integration tests (fail-safe). A similarly really cryptic error caused me to lose an entire day (argh! - please, Eclipse/TestNG, if you're going to give us errors, make them helpful). In my case it was because the accessor on the test method was private and needed to be public.

I hope someone else find this useful before an entire day is wasted.

edited Apr 15 '15 at 21:40

answered Mar 30 '15 at 23:35

Ted_Zactly

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When mvn install fails cryptically -

2 Answers2